2 package Moose::Util::TypeConstraints;
8 use List::MoreUtils qw( all );
9 use Scalar::Util 'blessed';
12 our $VERSION = '0.65';
13 $VERSION = eval $VERSION;
14 our $AUTHORITY = 'cpan:STEVAN';
16 ## --------------------------------------------------------
17 # Prototyped subs must be predeclared because we have a
18 # circular dependency with Moose::Meta::Attribute et. al.
19 # so in case of us being use'd first the predeclaration
20 # ensures the prototypes are in scope when consumers are
30 sub _create_type_constraint ($$$;$$);
31 sub _install_type_coercions ($$);
33 ## --------------------------------------------------------
35 use Moose::Meta::TypeConstraint;
36 use Moose::Meta::TypeConstraint::Union;
37 use Moose::Meta::TypeConstraint::Parameterized;
38 use Moose::Meta::TypeConstraint::Parameterizable;
39 use Moose::Meta::TypeConstraint::Class;
40 use Moose::Meta::TypeConstraint::Role;
41 use Moose::Meta::TypeConstraint::Enum;
42 use Moose::Meta::TypeCoercion;
43 use Moose::Meta::TypeCoercion::Union;
44 use Moose::Meta::TypeConstraint::Registry;
45 use Moose::Util::TypeConstraints::OptimizedConstraints;
47 Moose::Exporter->setup_import_methods(
50 type subtype class_type role_type maybe_type
51 as where message optimize_as
55 register_type_constraint )
60 ## --------------------------------------------------------
61 ## type registry and some useful functions for it
62 ## --------------------------------------------------------
64 my $REGISTRY = Moose::Meta::TypeConstraint::Registry->new;
66 sub get_type_constraint_registry { $REGISTRY }
67 sub list_all_type_constraints { keys %{$REGISTRY->type_constraints} }
68 sub export_type_constraints_as_functions {
71 foreach my $constraint (keys %{$REGISTRY->type_constraints}) {
72 my $tc = $REGISTRY->get_type_constraint($constraint)->_compiled_type_constraint;
73 *{"${pkg}::${constraint}"} = sub { $tc->($_[0]) ? 1 : undef }; # the undef is for compat
77 sub create_type_constraint_union {
78 my @type_constraint_names;
80 if (scalar @_ == 1 && _detect_type_constraint_union($_[0])) {
81 @type_constraint_names = _parse_type_constraint_union($_[0]);
84 @type_constraint_names = @_;
87 (scalar @type_constraint_names >= 2)
88 || __PACKAGE__->_throw_error("You must pass in at least 2 type names to make a union");
90 my @type_constraints = map {
91 find_or_parse_type_constraint($_) ||
92 __PACKAGE__->_throw_error("Could not locate type constraint ($_) for the union");
93 } @type_constraint_names;
95 return Moose::Meta::TypeConstraint::Union->new(
96 type_constraints => \@type_constraints
100 sub create_parameterized_type_constraint {
101 my $type_constraint_name = shift;
102 my ($base_type, $type_parameter) = _parse_parameterized_type_constraint($type_constraint_name);
104 (defined $base_type && defined $type_parameter)
105 || __PACKAGE__->_throw_error("Could not parse type name ($type_constraint_name) correctly");
107 if ($REGISTRY->has_type_constraint($base_type)) {
108 my $base_type_tc = $REGISTRY->get_type_constraint($base_type);
109 return _create_parameterized_type_constraint(
114 __PACKAGE__->_throw_error("Could not locate the base type ($base_type)");
118 sub _create_parameterized_type_constraint {
119 my ( $base_type_tc, $type_parameter ) = @_;
120 if ( $base_type_tc->can('parameterize') ) {
121 return $base_type_tc->parameterize($type_parameter);
123 return Moose::Meta::TypeConstraint::Parameterized->new(
124 name => $base_type_tc->name . '[' . $type_parameter . ']',
125 parent => $base_type_tc,
126 type_parameter => find_or_create_isa_type_constraint($type_parameter),
131 #should we also support optimized checks?
132 sub create_class_type_constraint {
133 my ( $class, $options ) = @_;
135 # too early for this check
136 #find_type_constraint("ClassName")->check($class)
137 # || __PACKAGE__->_throw_error("Can't create a class type constraint because '$class' is not a class name");
145 $options{name} ||= "__ANON__";
147 Moose::Meta::TypeConstraint::Class->new( %options );
150 sub create_role_type_constraint {
151 my ( $role, $options ) = @_;
153 # too early for this check
154 #find_type_constraint("ClassName")->check($class)
155 # || __PACKAGE__->_throw_error("Can't create a class type constraint because '$class' is not a class name");
163 $options{name} ||= "__ANON__";
165 Moose::Meta::TypeConstraint::Role->new( %options );
169 sub find_or_create_type_constraint {
170 my ( $type_constraint_name, $options_for_anon_type ) = @_;
172 if ( my $constraint = find_or_parse_type_constraint($type_constraint_name) ) {
175 elsif ( defined $options_for_anon_type ) {
177 # if there is no $options_for_anon_type
178 # specified, then we assume they don't
179 # want to create one, and return nothing.
181 # otherwise assume that we should create
182 # an ANON type with the $options_for_anon_type
183 # options which can be passed in. It should
184 # be noted that these don't get registered
185 # so we need to return it.
187 return Moose::Meta::TypeConstraint->new(
189 %{$options_for_anon_type}
196 sub find_or_create_isa_type_constraint {
197 my $type_constraint_name = shift;
198 find_or_parse_type_constraint($type_constraint_name) || create_class_type_constraint($type_constraint_name)
201 sub find_or_create_does_type_constraint {
202 my $type_constraint_name = shift;
203 find_or_parse_type_constraint($type_constraint_name) || create_role_type_constraint($type_constraint_name)
206 sub find_or_parse_type_constraint {
207 my $type_constraint_name = normalize_type_constraint_name(shift);
210 if ($constraint = find_type_constraint($type_constraint_name)) {
212 } elsif (_detect_type_constraint_union($type_constraint_name)) {
213 $constraint = create_type_constraint_union($type_constraint_name);
214 } elsif (_detect_parameterized_type_constraint($type_constraint_name)) {
215 $constraint = create_parameterized_type_constraint($type_constraint_name);
220 $REGISTRY->add_type_constraint($constraint);
224 sub normalize_type_constraint_name {
225 my $type_constraint_name = shift;
226 $type_constraint_name =~ s/\s//g;
227 return $type_constraint_name;
233 local $Carp::CarpLevel = $Carp::CarpLevel + 1;
234 Carp::confess($error);
237 ## --------------------------------------------------------
238 ## exported functions ...
239 ## --------------------------------------------------------
241 sub find_type_constraint {
244 if ( blessed $type and $type->isa("Moose::Meta::TypeConstraint") ) {
248 return unless $REGISTRY->has_type_constraint($type);
249 return $REGISTRY->get_type_constraint($type);
253 sub register_type_constraint {
254 my $constraint = shift;
255 __PACKAGE__->_throw_error("can't register an unnamed type constraint") unless defined $constraint->name;
256 $REGISTRY->add_type_constraint($constraint);
263 splice(@_, 1, 0, undef);
264 goto &_create_type_constraint;
269 # this adds an undef for the name
270 # if this is an anon-subtype:
271 # subtype(Num => where { $_ % 2 == 0 }) # anon 'even' subtype
273 # subtype(Num => where { $_ % 2 == 0 }) message { "$_ must be an even number" }
275 # but if the last arg is not a code ref then it is a subtype
278 # subtype(MyNumbers => as Num); # now MyNumbers is the same as Num
279 # ... yeah I know it's ugly code
281 unshift @_ => undef if scalar @_ == 2 && ( 'CODE' eq ref( $_[-1] ) );
283 if scalar @_ == 3 && all { ref($_) =~ /^(?:CODE|HASH)$/ } @_[ 1, 2 ];
284 goto &_create_type_constraint;
288 register_type_constraint(
289 create_class_type_constraint(
291 ( defined($_[1]) ? $_[1] : () ),
296 sub role_type ($;$) {
297 register_type_constraint(
298 create_role_type_constraint(
300 ( defined($_[1]) ? $_[1] : () ),
306 my ($type_parameter) = @_;
308 register_type_constraint(
309 $REGISTRY->get_type_constraint('Maybe')->parameterize($type_parameter)
314 my ($type_name, @coercion_map) = @_;
315 _install_type_coercions($type_name, \@coercion_map);
320 sub where (&) { $_[0] }
321 sub via (&) { $_[0] }
323 sub message (&) { +{ message => $_[0] } }
324 sub optimize_as (&) { +{ optimized => $_[0] } }
327 my ($type_name, @values) = @_;
329 # if only an array-ref is passed then
330 # you get an anon-enum
332 if (ref $type_name eq 'ARRAY' && !@values) {
333 @values = @$type_name;
336 (scalar @values >= 2)
337 || __PACKAGE__->_throw_error("You must have at least two values to enumerate through");
338 my %valid = map { $_ => 1 } @values;
340 register_type_constraint(
341 create_enum_type_constraint(
348 sub create_enum_type_constraint {
349 my ( $type_name, $values ) = @_;
351 Moose::Meta::TypeConstraint::Enum->new(
352 name => $type_name || '__ANON__',
357 ## --------------------------------------------------------
358 ## desugaring functions ...
359 ## --------------------------------------------------------
361 sub _create_type_constraint ($$$;$$) {
366 my ( $message, $optimized );
368 $message = $_->{message} if exists $_->{message};
369 $optimized = $_->{optimized} if exists $_->{optimized};
372 my $pkg_defined_in = scalar( caller(0) );
374 if ( defined $name ) {
375 my $type = $REGISTRY->get_type_constraint($name);
377 ( $type->_package_defined_in eq $pkg_defined_in )
379 "The type constraint '$name' has already been created in "
380 . $type->_package_defined_in
381 . " and cannot be created again in "
385 $name =~ /^[\w:\.]+$/
386 or die qq{$name contains invalid characters for a type name.}
387 . qq{Names can contain alphanumeric character, ":", and "."\n};
392 package_defined_in => $pkg_defined_in,
394 ( $check ? ( constraint => $check ) : () ),
395 ( $message ? ( message => $message ) : () ),
396 ( $optimized ? ( optimized => $optimized ) : () ),
402 = blessed $parent ? $parent : find_or_create_isa_type_constraint($parent) )
404 $constraint = $parent->create_child_type(%opts);
407 $constraint = Moose::Meta::TypeConstraint->new(%opts);
410 $REGISTRY->add_type_constraint($constraint)
416 sub _install_type_coercions ($$) {
417 my ($type_name, $coercion_map) = @_;
418 my $type = find_type_constraint($type_name);
420 || __PACKAGE__->_throw_error("Cannot find type '$type_name', perhaps you forgot to load it.");
421 if ($type->has_coercion) {
422 $type->coercion->add_type_coercions(@$coercion_map);
425 my $type_coercion = Moose::Meta::TypeCoercion->new(
426 type_coercion_map => $coercion_map,
427 type_constraint => $type
429 $type->coercion($type_coercion);
433 ## --------------------------------------------------------
434 ## type notation parsing ...
435 ## --------------------------------------------------------
438 # All I have to say is mugwump++ cause I know
439 # do not even have enough regexp-fu to be able
440 # to have written this (I can only barely
441 # understand it as it is)
446 my $valid_chars = qr{[\w:\.]};
447 my $type_atom = qr{ $valid_chars+ };
451 my $type = qr{ $valid_chars+ (?: \[ \s* (??{$any}) \s* \] )? }x;
452 my $type_capture_parts = qr{ ($valid_chars+) (?: \[ \s* ((??{$any})) \s* \] )? }x;
453 my $type_with_parameter = qr{ $valid_chars+ \[ \s* (??{$any}) \s* \] }x;
455 my $op_union = qr{ \s* \| \s* }x;
456 my $union = qr{ $type (?: $op_union $type )+ }x;
458 $any = qr{ $type | $union }x;
460 sub _parse_parameterized_type_constraint {
461 { no warnings 'void'; $any; } # force capture of interpolated lexical
462 $_[0] =~ m{ $type_capture_parts }x;
466 sub _detect_parameterized_type_constraint {
467 { no warnings 'void'; $any; } # force capture of interpolated lexical
468 $_[0] =~ m{ ^ $type_with_parameter $ }x;
471 sub _parse_type_constraint_union {
472 { no warnings 'void'; $any; } # force capture of interpolated lexical
475 while ( $given =~ m{ \G (?: $op_union )? ($type) }gcx ) {
478 (pos($given) eq length($given))
479 || __PACKAGE__->_throw_error("'$given' didn't parse (parse-pos="
487 sub _detect_type_constraint_union {
488 { no warnings 'void'; $any; } # force capture of interpolated lexical
489 $_[0] =~ m{^ $type $op_union $type ( $op_union .* )? $}x;
493 ## --------------------------------------------------------
494 # define some basic built-in types
495 ## --------------------------------------------------------
497 # By making these classes immutable before creating all the types we
498 # below, we avoid repeatedly calling the slow MOP-based accessors.
500 inline_constructor => 1,
501 constructor_name => "_new",
503 # these are Class::MOP accessors, so they need inlining
504 inline_accessors => 1
505 ) for grep { $_->is_mutable }
508 Moose::Meta::TypeConstraint
509 Moose::Meta::TypeConstraint::Union
510 Moose::Meta::TypeConstraint::Parameterized
511 Moose::Meta::TypeConstraint::Parameterizable
512 Moose::Meta::TypeConstraint::Class
513 Moose::Meta::TypeConstraint::Role
514 Moose::Meta::TypeConstraint::Enum
515 Moose::Meta::TypeConstraint::Registry
518 type 'Any' => where { 1 }; # meta-type including all
519 type 'Item' => where { 1 }; # base-type
521 subtype 'Undef' => as 'Item' => where { !defined($_) };
522 subtype 'Defined' => as 'Item' => where { defined($_) };
526 => where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
530 => where { !ref($_) }
531 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Value;
536 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Ref;
541 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Str;
545 => where { Scalar::Util::looks_like_number($_) }
546 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Num;
550 => where { "$_" =~ /^-?[0-9]+$/ }
551 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Int;
553 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::ScalarRef;
554 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::CodeRef;
555 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::RegexpRef;
556 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::GlobRef;
559 # scalar filehandles are GLOB refs,
560 # but a GLOB ref is not always a filehandle
563 => where { Scalar::Util::openhandle($_) || ( blessed($_) && $_->isa("IO::Handle") ) }
564 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::FileHandle;
567 # blessed(qr/.../) returns true,.. how odd
570 => where { blessed($_) && blessed($_) ne 'Regexp' }
571 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Object;
575 => where { $_->can('does') }
576 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Role;
578 my $_class_name_checker = sub {
583 => where { Class::MOP::is_class_loaded($_) }
584 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::ClassName;
586 ## --------------------------------------------------------
587 # parameterizable types ...
589 $REGISTRY->add_type_constraint(
590 Moose::Meta::TypeConstraint::Parameterizable->new(
592 package_defined_in => __PACKAGE__,
593 parent => find_type_constraint('Ref'),
594 constraint => sub { ref($_) eq 'ARRAY' },
595 optimized => \&Moose::Util::TypeConstraints::OptimizedConstraints::ArrayRef,
596 constraint_generator => sub {
597 my $type_parameter = shift;
598 my $check = $type_parameter->_compiled_type_constraint;
600 foreach my $x (@$_) {
601 ($check->($x)) || return
608 $REGISTRY->add_type_constraint(
609 Moose::Meta::TypeConstraint::Parameterizable->new(
611 package_defined_in => __PACKAGE__,
612 parent => find_type_constraint('Ref'),
613 constraint => sub { ref($_) eq 'HASH' },
614 optimized => \&Moose::Util::TypeConstraints::OptimizedConstraints::HashRef,
615 constraint_generator => sub {
616 my $type_parameter = shift;
617 my $check = $type_parameter->_compiled_type_constraint;
619 foreach my $x (values %$_) {
620 ($check->($x)) || return
627 $REGISTRY->add_type_constraint(
628 Moose::Meta::TypeConstraint::Parameterizable->new(
630 package_defined_in => __PACKAGE__,
631 parent => find_type_constraint('Item'),
632 constraint => sub { 1 },
633 constraint_generator => sub {
634 my $type_parameter = shift;
635 my $check = $type_parameter->_compiled_type_constraint;
637 return 1 if not(defined($_)) || $check->($_);
644 my @PARAMETERIZABLE_TYPES = map {
645 $REGISTRY->get_type_constraint($_)
646 } qw[ArrayRef HashRef Maybe];
648 sub get_all_parameterizable_types { @PARAMETERIZABLE_TYPES }
649 sub add_parameterizable_type {
651 (blessed $type && $type->isa('Moose::Meta::TypeConstraint::Parameterizable'))
652 || __PACKAGE__->_throw_error("Type must be a Moose::Meta::TypeConstraint::Parameterizable not $type");
653 push @PARAMETERIZABLE_TYPES => $type;
656 ## --------------------------------------------------------
657 # end of built-in types ...
658 ## --------------------------------------------------------
661 my @BUILTINS = list_all_type_constraints();
662 sub list_all_builtin_type_constraints { @BUILTINS }
668 goto &Moose::throw_error;
679 Moose::Util::TypeConstraints - Type constraint system for Moose
683 use Moose::Util::TypeConstraints;
685 type 'Num' => where { Scalar::Util::looks_like_number($_) };
691 subtype 'NaturalLessThanTen'
694 => message { "This number ($_) is not less than ten!" };
700 enum 'RGBColors' => qw(red green blue);
704 This module provides Moose with the ability to create custom type
705 contraints to be used in attribute definition.
707 =head2 Important Caveat
709 This is B<NOT> a type system for Perl 5. These are type constraints,
710 and they are not used by Moose unless you tell it to. No type
711 inference is performed, expression are not typed, etc. etc. etc.
713 This is simply a means of creating small constraint functions which
714 can be used to simplify your own type-checking code, with the added
715 side benefit of making your intentions clearer through self-documentation.
717 =head2 Slightly Less Important Caveat
719 It is B<always> a good idea to quote your type and subtype names.
721 This is to prevent perl from trying to execute the call as an indirect
722 object call. This issue only seems to come up when you have a subtype
723 the same name as a valid class, but when the issue does arise it tends
724 to be quite annoying to debug.
726 So for instance, this:
728 subtype DateTime => as Object => where { $_->isa('DateTime') };
730 will I<Just Work>, while this:
733 subtype DateTime => as Object => where { $_->isa('DateTime') };
735 will fail silently and cause many headaches. The simple way to solve
736 this, as well as future proof your subtypes from classes which have
737 yet to have been created yet, is to simply do this:
740 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
742 =head2 Default Type Constraints
744 This module also provides a simple hierarchy for Perl 5 types, here is
745 that hierarchy represented visually.
769 B<NOTE:> Any type followed by a type parameter C<[`a]> can be
770 parameterized, this means you can say:
772 ArrayRef[Int] # an array of integers
773 HashRef[CodeRef] # a hash of str to CODE ref mappings
774 Maybe[Str] # value may be a string, may be undefined
776 If Moose finds a name in brackets that it does not recognize as an
777 existing type, it assumes that this is a class name, for example
778 C<ArrayRef[DateTime]>.
780 B<NOTE:> Unless you parameterize a type, then it is invalid to
781 include the square brackets. I.e. C<ArrayRef[]> will be
782 literally interpreted as a type name.
784 B<NOTE:> The C<Undef> type constraint for the most part works
785 correctly now, but edge cases may still exist, please use it
788 B<NOTE:> The C<ClassName> type constraint does a complex package
789 existence check. This means that your class B<must> be loaded for
790 this type constraint to pass. I know this is not ideal for all,
791 but it is a saner restriction than most others.
793 =head2 Type Constraint Naming
795 Type name declared via this module can only contain alphanumeric
796 characters, colons (:), and periods (.).
798 Since the types created by this module are global, it is suggested
799 that you namespace your types just as you would namespace your
800 modules. So instead of creating a I<Color> type for your B<My::Graphics>
801 module, you would call the type I<My.Graphics.Color> instead.
803 =head2 Use with Other Constraint Modules
805 This module should play fairly nicely with other constraint
806 modules with only some slight tweaking. The C<where> clause
807 in types is expected to be a C<CODE> reference which checks
808 it's first argument and returns a boolean. Since most constraint
809 modules work in a similar way, it should be simple to adapt
810 them to work with Moose.
812 For instance, this is how you could use it with
813 L<Declare::Constraints::Simple> to declare a completely new type.
815 type 'HashOfArrayOfObjects'
818 -values => IsArrayRef( IsObject ));
820 For more examples see the F<t/200_examples/204_example_w_DCS.t>
823 Here is an example of using L<Test::Deep> and it's non-test
824 related C<eq_deeply> function.
826 type 'ArrayOfHashOfBarsAndRandomNumbers'
829 array_each(subhashof({
831 random_number => ignore()
835 For a complete example see the
836 F<t/200_examples/205_example_w_TestDeep.t> test file.
840 =head2 Type Constraint Constructors
842 The following functions are used to create type constraints.
843 They will then register the type constraints in a global store
844 where Moose can get to them if it needs to.
846 See the L<SYNOPSIS> for an example of how to use these.
850 =item B<type ($name, $where_clause)>
852 This creates a base type, which has no parent.
854 =item B<subtype ($name, $parent, $where_clause, ?$message)>
856 This creates a named subtype.
858 If you provide a parent that Moose does not recognize, it will
859 automatically create a new class type constraint for this name.
861 =item B<subtype ($parent, $where_clause, ?$message)>
863 This creates an unnamed subtype and will return the type
864 constraint meta-object, which will be an instance of
865 L<Moose::Meta::TypeConstraint>.
867 =item B<class_type ($class, ?$options)>
869 Creates a type constraint with the name C<$class> and the metaclass
870 L<Moose::Meta::TypeConstraint::Class>.
872 =item B<role_type ($role, ?$options)>
874 Creates a type constraint with the name C<$role> and the metaclass
875 L<Moose::Meta::TypeConstraint::Role>.
877 =item B<maybe_type ($type)>
879 Creates a type constraint for either C<undef> or something of the
882 =item B<enum ($name, @values)>
884 This will create a basic subtype for a given set of strings.
885 The resulting constraint will be a subtype of C<Str> and
886 will match any of the items in C<@values>. It is case sensitive.
887 See the L<SYNOPSIS> for a simple example.
889 B<NOTE:> This is not a true proper enum type, it is simple
890 a convient constraint builder.
892 =item B<enum (\@values)>
894 If passed an ARRAY reference instead of the C<$name>, C<@values> pair,
895 this will create an unnamed enum. This can then be used in an attribute
898 has 'sort_order' => (
900 isa => enum([qw[ ascending descending ]]),
905 This is just sugar for the type constraint construction syntax.
909 This is just sugar for the type constraint construction syntax.
911 Takes a block/code ref as an argument. When the type constraint is
912 tested, the supplied code is run with the value to be tested in
913 $_. This block should return true or false to indicate whether or not
914 the constraint check passed.
918 This is just sugar for the type constraint construction syntax.
920 Takes a block/code ref as an argument. When the type constraint fails,
921 then the code block is run (with the value provided in $_). This code
922 ref should return a string, which will be used in the text of the
927 This can be used to define a "hand optimized" version of your
928 type constraint which can be used to avoid traversing a subtype
929 constraint heirarchy.
931 B<NOTE:> You should only use this if you know what you are doing,
932 all the built in types use this, so your subtypes (assuming they
933 are shallow) will not likely need to use this.
937 =head2 Type Coercion Constructors
939 Type constraints can also contain type coercions as well. If you
940 ask your accessor to coerce, then Moose will run the type-coercion
941 code first, followed by the type constraint check. This feature
942 should be used carefully as it is very powerful and could easily
943 take off a limb if you are not careful.
945 See the L<SYNOPSIS> for an example of how to use these.
953 This is just sugar for the type coercion construction syntax.
957 This is just sugar for the type coercion construction syntax.
961 =head2 Type Constraint Construction & Locating
965 =item B<normalize_type_constraint_name ($type_constraint_name)>
967 Given a string that is expected to match a type constraint, will normalize the
968 string so that extra whitespace and newlines are removed.
970 =item B<create_type_constraint_union ($pipe_seperated_types | @type_constraint_names)>
972 Given string with C<$pipe_seperated_types> or a list of C<@type_constraint_names>,
973 this will return a L<Moose::Meta::TypeConstraint::Union> instance.
975 =item B<create_parameterized_type_constraint ($type_name)>
977 Given a C<$type_name> in the form of:
979 BaseType[ContainerType]
981 this will extract the base type and container type and build an instance of
982 L<Moose::Meta::TypeConstraint::Parameterized> for it.
984 =item B<create_class_type_constraint ($class, ?$options)>
986 Given a class name it will create a new L<Moose::Meta::TypeConstraint::Class>
987 object for that class name.
989 =item B<create_role_type_constraint ($role, ?$options)>
991 Given a role name it will create a new L<Moose::Meta::TypeConstraint::Role>
992 object for that role name.
994 =item B<create_enum_type_constraint ($name, $values)>
996 =item B<find_or_parse_type_constraint ($type_name)>
998 This will attempt to find or create a type constraint given the a C<$type_name>.
999 If it cannot find it in the registry, it will see if it should be a union or
1000 container type an create one if appropriate
1002 =item B<find_or_create_type_constraint ($type_name, ?$options_for_anon_type)>
1004 This function will first call C<find_or_parse_type_constraint> with the type name.
1006 If no type is found or created, but C<$options_for_anon_type> are provided, it
1007 will create the corresponding type.
1009 This was used by the C<does> and C<isa> parameters to L<Moose::Meta::Attribute>
1010 and are now superseded by C<find_or_create_isa_type_constraint> and
1011 C<find_or_create_does_type_constraint>.
1013 =item B<find_or_create_isa_type_constraint ($type_name)>
1015 =item B<find_or_create_does_type_constraint ($type_name)>
1017 Attempts to parse the type name using C<find_or_parse_type_constraint> and if
1018 no appropriate constraint is found will create a new anonymous one.
1020 The C<isa> variant will use C<create_class_type_constraint> and the C<does>
1021 variant will use C<create_role_type_constraint>.
1023 =item B<find_type_constraint ($type_name)>
1025 This function can be used to locate a specific type constraint
1026 meta-object, of the class L<Moose::Meta::TypeConstraint> or a
1027 derivative. What you do with it from there is up to you :)
1029 =item B<register_type_constraint ($type_object)>
1031 This function will register a named type constraint with the type registry.
1033 =item B<get_type_constraint_registry>
1035 Fetch the L<Moose::Meta::TypeConstraint::Registry> object which
1036 keeps track of all type constraints.
1038 =item B<list_all_type_constraints>
1040 This will return a list of type constraint names, you can then
1041 fetch them using C<find_type_constraint ($type_name)> if you
1044 =item B<list_all_builtin_type_constraints>
1046 This will return a list of builtin type constraints, meaning,
1047 those which are defined in this module. See the section
1048 labeled L<Default Type Constraints> for a complete list.
1050 =item B<export_type_constraints_as_functions>
1052 This will export all the current type constraints as functions
1053 into the caller's namespace. Right now, this is mostly used for
1054 testing, but it might prove useful to others.
1056 =item B<get_all_parameterizable_types>
1058 This returns all the parameterizable types that have been registered.
1060 =item B<add_parameterizable_type ($type)>
1062 Adds C<$type> to the list of parameterizable types
1066 =head2 Namespace Management
1072 This will remove all the type constraint keywords from the
1073 calling class namespace.
1079 All complex software has bugs lurking in it, and this module is no
1080 exception. If you find a bug please either email me, or add the bug
1085 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1087 =head1 COPYRIGHT AND LICENSE
1089 Copyright 2006-2008 by Infinity Interactive, Inc.
1091 L<http://www.iinteractive.com>
1093 This library is free software; you can redistribute it and/or modify
1094 it under the same terms as Perl itself.